/**
  * Return an string in the specified format for current configuration component.
  * 
  * @param string $configuration_type Type of configuration format to generate the string
  * @param array $options Specify special options for output
  * 
  * @return string The requested string
  */
 public function toString($configuration_type, array $options = array())
 {
     $return_value = null;
     $configuration_storage = __ConfigurationStorageFactory::getInstance()->createConfigurationStorage($configuration_type);
     if ($configuration_storage instanceof __ConfigurationStorage) {
         $return_value = $configuration_storage->toString($this, $options);
     }
     return $return_value;
 }
 /**
  * Load an given configuration file, returning a {@link __Configuration} instance representing it.
  *
  * The configuration file can be set as a relative path or absolute path.<br>
  * i.e.<br>
  * - config/controllers.xml (relative to the context root directory)<br>
  * - /var/www/myapp/config.xml (absolute path)<br>
  * 
  * @param string $configuration_file The configurl or physical configuration file
  * @return __Configuration The loaded {@link __Configuration} instance
  */
 public function &loadConfigurationFile($configuration_file)
 {
     $return_value = null;
     $configuration_file = __PathResolver::resolvePath($configuration_file);
     if (__Lion::getInstance()->getRuntimeDirectives()->getDirective('DEBUG_MODE')) {
         $this->_configuration_files_mtimes[$configuration_file] = @filemtime($configuration_file);
     }
     $configuration_file_type = $this->_getConfigurationFileType($configuration_file);
     if (is_readable($configuration_file) && is_file($configuration_file)) {
         $return_value = $this->createConfiguration();
         $configuration_storage = __ConfigurationStorageFactory::createConfigurationStorage($configuration_file_type);
         $configuration_storage->load($configuration_file, $return_value);
         $return_value = $this->_parseIncludes($return_value, dirname($configuration_file));
     } else {
         throw new __ConfigurationException('Configuration file "' . $configuration_file . '" not found or not readable.');
     }
     return $return_value;
 }